ATMEGA644PA-PU Atmel, ATMEGA644PA-PU Datasheet - Page 138

• Manufacturer Part Number: ATMEGA644PA-PU
• Description: IC MCU 8BIT 64KB FLASH 40DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644PA-PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, TWI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.11.7
15.11.8
8272A–AVR–01/10
ICR1H and ICR1L – Input Capture Register 1
TIMSK1 – Timer/Counter1 Interrupt Mask Register
The Input Capture is updated with the counter (TCNTn) value each time an event occurs on the
ICPn pin (or optionally on the Analog Comparator output for Timer/Counter1). The Input Capture
can be used for defining the counter TOP value.
The Input Capture Register is 16-bit in size. To ensure that both the high and low bytes are read
simultaneously when the CPU accesses these registers, the access is performed using an 8-bit
temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit
registers.
• Bit 7:6 – Res: Reserved Bits
These bits are unused bits in the ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P,
and will always read as zero.
• Bit 5 – ICIE1: Timer/Counter1, Input Capture Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally
enabled), the Timer/Counter1 Input Capture interrupt is enabled. The corresponding Interrupt
Vector (see “Interrupts” on page 62) is executed when the ICF1 Flag, located in TIFR1, is set.
• Bit 4:3 – Res: Reserved Bits
These bits are unused bits in the ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P,
and will always read as zero.
• Bit 2 – OCIE1B: Timer/Counter1, Output Compare B Match Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally
enabled), the Timer/Counter1 Output Compare B Match interrupt is enabled. The corresponding
Interrupt Vector (see “Interrupts” on page 62) is executed when the OCF1B Flag, located in
TIFR1, is set.
• Bit 1 – OCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally
enabled), the Timer/Counter1 Output Compare A Match interrupt is enabled. The corresponding
Interrupt Vector (see “Interrupts” on page 62) is executed when the OCF1A Flag, located in
TIFR1, is set.
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Bit
(0x87)
(0x86)
Read/Write
Initial Value
Bit
(0x6F)
Read/Write
Initial Value
See Section “15.3” on page 114.
R/W
R
7
0
7
–
0
R/W
R
6
–
0
6
0
ICIE1
R/W
R/W
5
0
5
0
R/W
R
4
–
0
4
0
ICR1[15:8]
ICR1[7:0]
R/W
R
3
–
0
3
0
OCIE1B
R/W
R/W
2
0
2
0
OCIE1A
R/W
R/W
1
0
1
0
TOIE1
R/W
R/W
0
0
0
0
TIMSK1
ICR1H
ICR1L
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